Found the bug, should be working now. There is a little explanation in the Change Log:

EDIT: Here is the entire Change Log, just for anyone who is interested:

Febuary 17, 2015

Fixed an issue that could cause Statistics page to not show up for users with less than 12 months worth of sales.

Febuary 15, 2015

Transitioned to Google Charts. All problems with the chart tooltips should be gone.

Moved the color scheme picker from Settings to the Statistics screen. You can now click a button in the top right corner, choose a color scheme and instantly see how your charts will look like and it’s saved automatically.

Febuary 14, 2015

Referral cuts are now calculated in all statistics, except “Earnings by product, last 12 months” and “Total amount earned per product”.

Febuary 11, 2015

Fixed a bug where product names in the statement containing hyphens would display it’s character code, instead of the symbol.

The “Earnings Total” in statistics now takes into account the author fees, sale reversals, referral cuts and manual adjustments.

Febuary 8, 2015

Improved the accuracy of “Average per day” and “Estimated this month”. “Average per day” now calculates it’s value based on hours (720 hours back, which is exactly 30 days), instead of whole days. As a result, the value shouldn’t drop as soon as it’s 00:00:00 AM and go back up when it’s near 23:59:00, but it should stay more stable and accurate during the whole day.

Febuary 7, 2015

Completely reworked the mouse/touch event system. This should fix the unintended button clicks/taps and the inability to scroll the screen on touchscreen devices in certain situations.

CSV upload has been tested and it’s working again. No changes have been made to the database.

Febuary 5, 2015

The CSV upload feature has been temporarily turned off (until Sunday most likely). This is due to the changes to the statements Envato made on Febuary 1st.

Febuary 1, 2015

The new Author Fee is now calculated into all statistics.

Adjusted the tooltips for each chart. The tooltip in “Total amount earned per product” no longer shows how much exactly you have earned, because after the changes to the Envato API you can’t subtract the Author Fee for each individual product (meaning that you get an Author Fee record in your statement, but there is no way to know for sure for which product it is), which means that the actual amount data is no longer reliable.

January 31, 2015

Withdrawals are no longer calculated when displaying the amount you have earned today on the home screen.

The “Estimated this month” value in Statistics is now calculated based on the hours remaining this month, instead of days remaining.

The “Estimated this month” value in Statistics is now visualised in the “Earnings last 12 months” chart.

The new Author Fee is now calculated in the amount you have earned today and is no longer displayed in your statement.

January 29, 2015

Fixed a bug in Settings screen. When you click the “Upload a .csv” container it will no longer collapse the table cell.

January 24, 2015

Added color schemes for statistics charts

Improved layout of the Settings screen

Fixed an issue with the “Earnings last 30 days” chart, where it would show wrong data if there was a day with 0 sales.

The products in the “Total amount earned per product” are now sorted.

The labels in the “Earnings by product, last 12 months” popup are now sorted according to the actual data. They were reversed before.

Just a quick update – I’m currently implementing Google Charts to make the charts more usable, for example the monster “Earnings by product” chart. Here is a preview:

Notice the tooltip – you can now clearly see which item corresponds to each line. This will benefit the pie chart as well:

However I still have lots of work to do, like make sure the charts are responsive and make them more pretty. Also I would really like to keep the colour palettes that you can choose from the Settings screen, hopefully that won’t be too difficult.

magethemes said
One more suggestion, when I hover on graphs point with my mouse, or tap it on mobile device, maybe to draw ticker line going to x and y axis so its easier for me to see it values, maybe even to bold values.

I’m going to switch to Google Charts eventually and I think they offer many more features (and working tooltips) than Chart.js that I’m currently using.